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FDA Approves Femara for Early-stage Breast Cancer (dateline February 15, 2006)

The U.S. Food and Drug Administration (FDA) has approved the drug Femara (generic name, letrozole) for the treatment of post-menopausal, early-stage breast cancer after surgery. The approval comes after the results of a recent study found that Femara was better than the standard drug tamoxifen (brand name, Nolvadex) at preventing a recurrence of breast cancer in patients with early stages of the disease who had undergone surgery. Femara is already FDA-approved to treat advanced breast cancer. The new approval provides more treatment options for early-stage breast cancer patients after surgery.

According to study results published in the December 29, 2005 issue of The New England Journal of Medicine, 84% post-menopausal early-stage breast cancer patients who receive Femara would survive five years after their diagnosis versus 81.4% who receive tamoxifen.

The study was conducted by researchers of the International Breast Cancer Study Group, a non-profit group, in 27 countries. It included more than 8,000 post-menopausal women who had been diagnosed with estrogen-receptor-positive, early-stage breast cancer. Researchers followed the women for a median time of 26 months, with 1,100 women having completed five years of treatment with Femara or tamoxifen. Financial support for the study was provided by Novartis, the manufacturer of Femara.

Early-stage breast cancer is cancer that has not spread past the breast and/or underarm lymph nodes. Most early-stage breast cancer patients undergo surgery and may also receive radiation and/or chemotherapy. About 80% of breast cancer cases are estrogen-receptor-positive, meaning that the cancer cells depend on estrogen for survival and reproduction. Tamoxifen is also indicated for this type of breast cancer.

According to Novartis, the manufacturer of Femara, the study found that Femara was especially effective in women at high risk for a breast cancer recurrence. For example, in women whose breast cancer had spread to the underarm lymph nodes, Femara reduced the risk of a breast cancer recurrence by 29%. Similarly, Femara reduced the risk of a recurrence by 30% in women who had received chemotherapy. Moreover, Femara appeared to reduce the risk of a recurrence of breast cancer in distant body parts (such as the bone) in these women by 33% and 31%, respectively.

"One of the greatest fears confronted by women who have been treated for early breast cancer is that their cancer will come back," said Matthew Ellis, MD, PhD, FRCP, director of the Breast Cancer Program at Washington University and associate professor and section head of the Medical Oncology Division in the Department of Medicine at Washington University in St. Louis, in a Novartis news release. "With Femara, we now have an option that can help address that fear early on, even in the patients who we know face the greatest risk of recurrence."

Side effects differ among the two drugs. In the study, women who received tamoxifen were more likely to experience blood clots (venous thrombosis and embolism), vaginal bleeding, or abnormalities of the endometrium (the lining of the uterus). In contrast, women who received Femara were more likely to experience bone fractures or joint pain. In addition, women who received tamoxifen were more likely to develop invasive endometrial cancer and women who received Femara were more likely to experience life-threatening cardiac events, though the occurrence of these complications was rare--occurring in less than 1% of study participants.

Further research will likely continue to study the benefits of both Femara and tamoxifen in the treatment of early-stage breast cancer. Women diagnosed with breast cancer should talk to their cancer treatment team about the most appropriate treatments given their individual medical situations.

Additional Resources and References

  • The study, "Comparison of Letrozole and Tamoxifen in Postmenopausal Women with Early Breast Cancer," is published in the December 29, 2005 issue of The New England Journal of Medicine (
  • The December 28, 2005 International Breast Cancer Study Group news release, "Letrozole Better Than Tamoxifen in Reducing Risk of Recurrence for Breast Cancer Survivors," was published on the group's website,
  • The December 28, 2005 Novartis news release, "Femara┬« Approved in the US as Initial Therapy for Postmenopausal Women with Early Breast Cancer After Surgery," was published on the company's website,
  • The February 21, 2005 article, "Large Study Shows Femara May Be More Effective Than Tamoxifen at Treating Early-Stage Breast Cancer" is available at
  • To learn more about drugs used to treat breast cancer, please visit